Display Device

ABSTRACT

According to an aspect, a display device includes: a substrate including a display region and a non-display region surrounding the display region; at least one driver IC including connecting terminals with a first surface fixed to face the non-display region; first wires supplying a signal to the display region; first bumps connected with the first wires; second wires transferring a signal to and from outside; second bumps connected with the second wires; and inspection wires. The connecting terminals of the driver IC include first connecting terminals overlapping the first or second bumps in plan view, and second connecting terminals not overlapping the first or second bumps in plan view. The inspection wires include a connecting conductor between themselves and at least one of the second connecting terminals. The inspection wires are pulled out to an outside of the driver IC in plan view.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Japanese Application No.2016-073038, filed on Mar. 31, 2016, the contents of which areincorporated by reference herein in its entirety.

BACKGROUND 1. Technical Field

The present invention relates to a display device.

2. Description of the Related Art

A display device includes a substrate in which pixels are formed, and adriver integrated circuit (IC) on which a drive circuit is formed. Thedrive circuit is connected with an external control device through aflexible substrate. There is also an input detection device, orso-called a touch panel, which can detect an external proximity object.A substrate on which a detection electrode of the touch panel is formedalso includes a drive circuit that drives the detection electrode, andthe drive circuit may be connected with the flexible substrate in somecases.

Japanese Patent Application Laid-open Publication No. 2009-224505 andJapanese Patent Application Laid-open Publication No. 2007-47259disclose, as a method of connecting the substrate with the flexiblesubstrate, a method of arranging an anisotropic conductive film (ACF)between the substrate and the flexible substrate and connecting thesubstrate with the flexible substrate by means of crimping using acrimping head.

By the way, the driver IC on which the drive circuit is formed and aconnecting electrode of the substrate, called a bump, are connected witheach other through a conductive material such as ACF. Detectability of acoupling state between a terminal of the driver IC and the connectingelectrode of the substrate can improve reliability of electricalconnection of the display device.

For the foregoing reasons, there is a need for a display device that candetect an electrical coupling state between a driver IC and a substrate.

SUMMARY

According to an aspect, a display device includes: a substrate includinga display region and a non-display region that is disposed on aperiphery of the display region; at least one driver IC including aplurality of connecting terminals, and having a first surface that isfixed to face the non-display region; a plurality of first wires thatsupply a signal to the display region; a plurality of first bumpselectrically connected with the respective first wires; a plurality ofsecond wires that input and output a signal from and to an outside; aplurality of second bumps electrically connected with the respectivesecond wires; and a plurality of inspection wires. The connectingterminals of the at least one driver IC comprise a plurality of firstconnecting terminals overlapping the respective first bumps or therespective second bumps in plan view, and a plurality of secondconnecting terminals not overlapping the first bumps or the second bumpsin plan view. The inspection wires include a connecting conductorbetween themselves and at least one of the second connecting terminals.The inspection wires are pulled out to an outside of the at least onedriver IC in plan view.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory diagram illustrating an example of a displaydevice according to an embodiment;

FIG. 2 is a sectional view illustrating an example of a display unit;

FIG. 3 is a block diagram illustrating the display device of FIG. 1;

FIG. 4 is a circuit diagram illustrating an example of a pixel circuit;

FIG. 5 is a plan view schematically illustrating a plurality of wireselectrically connecting a scanning line drive circuit with scanninglines;

FIG. 6 is a plan view schematically illustrating terminals of a driverIC;

FIG. 7 is an enlarged schematic view illustrating connecting electrodesand wires of a substrate on which the terminals of the driver ICaccording to the first embodiment are mounted;

FIG. 8 is a schematic view illustrating a cross section taken along lineVIII-VIII in FIG. 7;

FIGS. 9A and 9B are schematic views for each describing a positionalrelationship between the terminals of the driver IC and the connectingelectrodes of the substrate;

FIG. 10 is an enlarged schematic view illustrating connecting electrodesand wires of a substrate on which terminals of a driver IC according toa second embodiment are mounted;

FIG. 11 is a schematic view illustrating a cross section taken alongline XI-XI in FIG. 10;

FIG. 12 is an enlarged schematic view illustrating connecting electrodesand wires of a substrate on which terminals of a driver IC according toa first modification of the second embodiment are mounted;

FIG. 13 is an enlarged schematic view illustrating connecting electrodesand wires of a substrate on which terminals of a driver IC according toa second modification of the second embodiment are mounted;

FIG. 14 is an enlarged schematic view illustrating connecting electrodesand wires of a substrate on which terminals of a driver IC according toa third embodiment are mounted;

FIG. 15 is an enlarged schematic view illustrating connecting electrodesand wires of a substrate on which terminals of a driver IC according toa first modification of the third embodiment are mounted; and

FIGS. 16A to 16C are explanatory diagrams for describing evaluationexamples of the third embodiment.

DETAILED DESCRIPTION

Modes (embodiments) for carrying out the present invention will bedescribed below in detail with reference to the drawings. The contentsdescribed in the embodiments are not intended to limit the presentinvention. Components described below include components easilyconceivable by those skilled in the art and components substantiallyidentical therewith. Furthermore, the components described below can beappropriately combined. The disclosure is given by way of example only,and various changes made without departing from the spirit of theinvention and easily conceivable by those skilled in the art naturallyfall within the scope of the invention. The drawings may possiblyillustrate the width, the thickness, the shape, and other elements ofeach unit more schematically than the actual aspect to simplify theexplanation. These elements, however, are given by way of example onlyand are not intended to limit interpretation of the invention. In thespecification and the figures, components similar to those previouslydescribed with reference to a preceding figure are denoted by likereference numerals, and overlapping explanation thereof will beappropriately omitted.

First Embodiment

FIG. 1 is an explanatory diagram illustrating an example of a displaydevice according to the present embodiment, FIG. 2 is a sectional viewillustrating an example of the display unit, FIG. 3 is a block diagramillustrating the display device of FIG. 1, and FIG. 4 is a circuitdiagram illustrating an example of a pixel circuit. FIG. 1 isschematically illustrated, and the dimensions and shapes are notnecessarily the same as the actual dimensions and shapes.

As illustrated in FIG. 1, a display device 1 includes a display unit 2and a backlight 6. The display device 1 may be a transmissive ortransflective display device, or may be a reflective display device notincluding the backlight 6.

The display unit 2 includes a display region 21 in which an image isdisplayed and a frame region 29 as a non-display region in which animage cannot be displayed, in plan view. The frame region 29 is providedon the periphery of the display region 21. In the present embodiment, adirection on a plane of the display unit 2 is an X direction, adirection perpendicular to the X direction is a Y direction, and adirection perpendicular to an X-Y plane is a Z direction. The displayregion 21 has a rectangular shape, and is a region surrounded by a firstside 21 a, a second side 21 b, a third side 21 c, and a fourth side 21d.

The backlight 6 is disposed on a back surface side of the display unit 2(on a surface opposite to a surface where an image is displayed asviewed in the Z direction). The backlight 6 irradiates the display unit2 with light, and causes the light to enter the entire surface of thedisplay region 21. The backlight 6 includes, for example, a light sourceand a light-guiding plate that guides the light output from the lightsource to emit toward the back surface of the display unit 2. Thebacklight 6 may include a plurality of light sources arranged in the Xdirection or the Y direction, and the amounts of light of the respectivelight sources may be independently controlled. Accordingly, thebacklight 6 can cause the light to enter a part of the display unit 2with light emitted from only a part of the light sources. In the displaydevice 1 of the present embodiment, the backlight 6 disposed on the backsurface side of the display unit 2 will be described as the lightsource. However, the light source may be a front light disposed on afront surface side of the display unit 2.

FIG. 2 is a sectional view illustrating an example of the display unit.As illustrated in FIG. 2, the display unit 2 includes a first substrate(upper substrate) 50, a second substrate (lower substrate) 52 disposedto face a surface of the first substrate 50 in a direction perpendicularto the surface of the first substrate 50 (the Z direction illustrated inFIG. 1), and a liquid crystal layer 54 interposed between the firstsubstrate 50 and the second substrate 52. The backlight 6 is disposed ona surface of the first substrate 50, the surface being opposite to asurface thereof on which the liquid crystal layer 54 is disposed.

A large number of liquid crystals are dispersed in the liquid crystallayer 54. The liquid crystals of the liquid crystal layer 54 modulatelight passing therethrough according to a state of an electric field,and are liquid crystals that are driven in a transverse electric fieldmode such as a fringe field switching (FFS) mode or an in-planeswitching (IPS) mode. The liquid crystals of the liquid crystal layer 54may be liquid crystals in other modes such as a twisted nematic (TN)mode, a vertical alignment (VA), and an electrically controlledbirefringence (ECB) mode.

The first substrate 50 includes a pixel substrate 60 as a translucentsubstrate such as glass, a first orientation member 62 laminated on thepixel substrate 60 on the liquid crystal layer 54 side, and a firstpolarizing plate 63 laminated on the pixel substrate 60 on the oppositeside of the liquid crystal layer 54. The pixel substrate 60 will bedescribed below. The first orientation member 62 orientates liquidcrystal molecules in the liquid crystal layer 54 in a predetermineddirection, and is directly in contact with the liquid crystal layer 54.The first orientation member 62 is made of, for example, a polymericmaterial such as polyimide, and is formed by the applied polyimide orthe like being subjected to rubbing treatment, for example. The firstpolarizing plate 63 has a function to convert the light entering fromthe backlight 6 side into linearly polarized light.

The second substrate 52 includes a counter substrate 64 as a translucentsubstrate such as glass, a color filter 66 formed on the countersubstrate 64 on the liquid crystal layer 54 side, a second orientationmember 67 formed on the color filter 66 on the liquid crystal layer 54side, a phase difference plate 68 formed on the counter substrate 64 onthe opposite side of the liquid crystal layer 54 side, and a secondpolarizing plate 69 formed on the phase difference plate 68 on theopposite side of the counter substrate 64 side.

As illustrated in FIG. 3, a large number of pixels Vpix are arranged inthe display region 21 in a matrix. A scanning line drive circuit 22 anda signal line drive circuit 23 are arranged in a frame region 29 aoutside the first side 21 a of the display region 21.

As illustrated in FIG. 3, the display region 21 has a structure in whichthe pixels Vpix including the liquid crystal layer, each of which servesas a unit that constitutes one pixel to be displayed, are arranged in anm row by n column matrix. In this specification, a row refers to a pixelrow including m pixels Vpix arrayed in one direction. A column refers toa pixel column including n pixels Vpix arrayed in a directionperpendicular to the direction in which the row is arrayed. Further,values of m and n are determined according to a display resolution in avertical direction and a display resolution in a horizontal direction.

In the display region 21, scanning lines 24 ₁, 24 ₂, 24 ₃, . . . 24 _(m)are arranged on a row to row basis, and signal lines 25 ₁, 25 ₂, 25 ₃,25 ₄, 25 ₅, . . . 25 _(n) are arranged on a column to column basis, forthe m row by n column array of the pixels Vpix. Hereinafter, in thepresent embodiment, the scanning lines 24 ₁, 24 ₂, 24 ₃, . . . 24 _(m)may be collectively described as scanning line 24, and the signal lines25 ₁, 25 ₂, 25 ₃, . . . 25 _(n) may be collectively described as signalline 25.

In the display region 21, the scanning line 24 and the signal line 25are arranged so as to overlap a black matrix 76 a in the same layer asthe color filter 66 (see FIG. 2) in plan view (Z direction). In thedisplay region 21, a region where the black matrix 76 a is not arrangedis an opening portion 76 b.

The color filter 66 illustrated in FIG. 2 includes color regions coloredinto three colors of red (R), green (G), and blue (B), for example. Inthe color filter 66, the color regions colored into the three colors ofred (R), green (G), and blue (B) are periodically arrayed in the openingportions 76 b illustrated in FIG. 4, and a pixel Pix corresponds to aset of the color regions having the respective three colors of R, G, andB corresponding to the respective pixels Vpix. Therefore, the pixel Vpixis also called a sub-pixel. The color filter 66 faces the liquid crystallayer 54 in a direction perpendicular to the pixel substrate 60. Anycombination of colors may be employed as long as the color filter 66 iscolored into different colors. The color filter 66 may be formed so thatthe black matrix 76 a covers an outer periphery of the pixels Vpixillustrated in FIG. 3. This black matrix 76 a is disposed on theboundary of the pixels Vpix, which are two-dimensionally arranged,thereby forming a lattice shape. Further, the black matrix 76 a isformed of a material having a higher optical absorption rate than thatof the color filter 66.

As illustrated in FIG. 2, the second orientation member 67 orientatesthe liquid crystal molecules in the liquid crystal layer 54 in apredetermined direction, and is directly in contact with the liquidcrystal layer 54, similarly to the first orientation member 62. Thesecond orientation member 67 is made of, for example, a polymericmaterial such as polyimide, and is formed by the applied polyimide orthe like being subjected to rubbing treatment, for example. The phasedifference plate 68 has a function to compensate changes in view anglecaused by the first polarizing plate 63 and the second polarizing plate69. The second polarizing plate 69 has a function to absorb a linearlypolarized light component parallel to a polarizing plate absorptionaxis, and transmit a polarization component perpendicular to thepolarizing plate absorption axis. The second polarizing plate 69 has afunction to transmit/block the light, depending on an ON/OFF state ofthe liquid crystals.

The scanning line drive circuit 22 illustrated in FIG. 4 outputs digitaldata of one line supplied from the outside as a scanning signal insequence, and sequentially scans the pixels Vpix row by row by providingthe scanning signal to each of the scanning lines 24 ₁, 24 ₂, 24 ₃, . .. 24 _(m) of the display region 21. The scanning line drive circuit 22outputs the digital data in sequence from a vertical scanning upperdirection to a vertical scanning lower direction, i.e., from thescanning line 24 ₁ to the scanning line 24 _(m) (in the Y direction).The scanning line drive circuit 22 may output the digital data insequence from the vertical scanning lower direction to the verticalscanning upper direction.

R (red), G (green), or B (blue) 6-bit digital video data is provided tothe signal line drive circuit 23, for example. The signal line drivecircuit 23 writes display data through the signal line 25 to the pixelsVpix of a row vertically scanned by the scanning line drive circuit 22,on a pixel to pixel basis, on a sub-pixels to sub-pixels basis, or tothe sub-pixels all together.

A large number of pixel circuits including active elements (for example,thin film transistors) are arranged on the pixel substrate 60illustrated in FIG. 2 in a matrix in plan view. Wires such as the signalline 25 and the scanning line 24 are formed in the display region 21.The signal line 25 supplies a pixel signal as display data to thin filmtransistors (TFTs) Tr of the pixels Vpix illustrated in FIG. 4, and thescanning line 24 drives the thin film transistors Tr. In this way, thesignal line 25 extend on a plane parallel to the surface of the pixelsubstrate 60, and supplies the pixel signal for displaying an image tothe pixels Vpix. The pixel Vpix includes the thin film transistor Tr anda liquid crystal capacitance LC. In this example, the thin filmtransistor Tr is configured by a n-channel metal oxide semiconductor(MOS)-type TFT. One of the source and the drain of the thin filmtransistor Tr is connected with the signal line 25, the gate thereof isconnected with the scanning line 24, and the other of the source and thedrain is connected with one end of the liquid crystal capacitance LC.One end of the liquid crystal capacitance LC is connected with the thinfilm transistor Tr, and the other end thereof is connected with a commonpotential of a common electrode com. In this way, the common potentialcommonly provided to the pixels is provided to a pixel electrode of eachpixel Vpix in the display region 21.

The pixel Vpix is connected with other pixels Vpix belonging to the samerow of the display region 21 through the scanning line 24. The scanninglines 24 extend along the pixels Pix or the row in which the pixels Vpixare arrayed. The scanning lines are connected with the scanning linedrive circuit 22. The scanning lines 24 are supplied with the scanningsignals from the scanning line drive circuit 22. The pixel Vpix isconnected with other pixels Vpix belong to the same column of thedisplay region 21 through the signal line 25. The signal lines 25 areconnected with the signal line drive circuit 23, and are supplied withthe pixel signals from the signal line drive circuit 23. The commonpotential of the common electrode com is connected with a driveelectrode driver (not illustrated), and is supplied a voltage from thedrive electrode driver. Further, the pixel Vpix is connected with otherpixels Vpix belonging to the same column of the display region 21through the common potential of the common electrode com.

FIG. 5 is a plan view schematically illustrating a plurality of wireselectrically connecting a scanning line drive circuit with scanninglines. Each of the scanning line drive circuit 22 and the signal linedrive circuit 23 is an integrated circuit called a chip on glass (COG),and is referred to as a driver IC. In the present embodiment, aplurality of the signal line drive circuits 23 are provided, but onedriver IC may be provided. In the present embodiment, the scanning linedrive circuit 22 and the signal line drive circuit 23 are provided asindividual driver ICs, but may be provided as a single driver IC.Alternatively, the scanning line drive circuit 22 and the signal linedrive circuit 23 together with the above-described drive electrodedriver may be provided as a single driver IC.

The scanning line drive circuit 22 applies the scanning signals to thegates of the thin film transistors Tr of the pixels Vpix through aplurality of wires 100 illustrated in FIGS. 3 and 5 and the scanninglines 24 (scanning lines 24 _(k), 24 ₂, 24 ₃, . . . 24 _(m)) illustratedin FIG. 3. Accordingly, one row (one horizontal line) of the pixels Vpixof the display region 21 is sequentially selected as an object to bedriven and displayed.

The signal line drive circuit 23 supplies the pixel signals to thepixels Vpix of the one horizontal line sequentially selected by thescanning line drive circuit 22, through a plurality of wires 200illustrated in FIGS. 3 and 5 and the signal lines 25 (signal lines 25_(k), 25 ₂, 25 ₃, 25 ₄, 25 ₅, . . . 25 _(n)) illustrated in FIG. 3.Then, in these pixels Vpix, display of one horizontal line is performedaccording to the supplied pixel signals.

As illustrated in FIG. 5, the wires 200 are arranged in the frame region29 a outside the first side 21 a of the display region 21. The wires 200electrically connect the signal line drive circuit 23 with the signallines 25 illustrated in FIG. 3. The wires 200 are a conductive patternformed of an aluminum (Al) or an aluminum alloy conductor.Alternatively, the wires 200 may be a conductive pattern formed of aconductor in which two types or more of conductive metals, such asaluminum (Al), titanium (Ti), and molybdenum (Mo), are laminated.

The number of the wires 200 is the same as the number of the signallines 25. The number of the signal lines 25 is increased as a resolutionof the display region 21 is increased. Therefore, the number of thewires 200 is also increased as the resolution of the display region 21is increased. The present embodiment employs a configuration in whichthree signal line drive circuits 23 are provided. Therefore, one side ofone signal line drive circuit 23 is made not too long compared with theother side thereof.

As illustrated in FIG. 5, the wires 100 are arranged in the frame region29 b outside the second side 21 b of the display region 21, the secondside 21 b being perpendicular to the first side 21 a of the displayregion 21. The wires 100 electrically connect the scanning line drivecircuit 22 with the respective scanning lines 24. The wires 100 are aconductive pattern formed of an aluminum (Al) or an aluminum alloyconductor, for example. Alternatively, the wires 100 may be a conductivepattern formed of a conductor in which two types or more of conductivemetals, such as aluminum (Al), titanium (Ti), and molybdenum (Mo), arelaminated.

The number of the wires 100 is the same as the number of the scanninglines 24. The number of the scanning lines 24 is increased as theresolution of the display region 21 is increased. Therefore, the numberof the wires 100 is also increased as the resolution of the displayregion 21 is increased. Therefore, the width in the X direction of thewires 100 arranged in the limited frame region 29 b becomes smaller asthe resolution of the display region 21 is increased.

FIG. 6 is a plan view schematically illustrating terminals of a driverIC. FIG. 7 is an enlarged schematic view illustrating connectingelectrodes and wires of a substrate on which the terminals of the driverIC according to the first embodiment are mounted. FIG. 8 is a schematicview illustrating a cross section taken along line VIII-VIII in FIG. 7.FIGS. 9A and 9B are schematic views for each describing a positionalrelationship between the terminals of the driver IC and the connectingelectrodes of the substrate. FIGS. 9A and 9B are schematic views of theterminals of the driver IC and the connecting electrodes of thesubstrate as viewed from a side surface. As illustrated in FIGS. 6 and9A and 9B, the driver IC of the signal line drive circuit 23 is a cubehaving a first surface 23 a, a second surface 23 b, a third surface 23c, a fourth surface 23 d, a fifth surface 23 e, and a sixth surface 23f. The first surface 23 a faces the second surface 23 b. The thirdsurface 23 c faces the fourth surface 23 d. The fifth surface 23 e facesthe sixth surface 23 f. The driver IC illustrated in FIG. 9A has anormal shape. In contrast, the driver IC illustrated in FIG. 9B has acurve such that a central portion in the Y direction of the firstsurface 23 a is recessed.

As illustrated in FIG. 8, a connecting terminal 32 is electricallyconnected with a third bump 42 through a connecting conductor 49. Sincethe connecting terminals 32 are short-circuited in internal wires 39,the third bumps 42 are also short-circuited through the connectingterminal 32, the internal wires 39, and the connecting terminal 32.

A plurality of connecting terminals 31, 32, 34, and 35 illustrated inFIG. 6 are exposed on the first surface 23 a illustrated in FIG. 9A. Inthis way, the signal line drive circuit 23 is a driver IC of a face-downmethod that causes the first surface 23 a to face the pixel substrate60.

As illustrated in FIG. 6, the connecting terminals 31 and 32 arearranged to form a plurality of columns as viewed in the X directionthat is a longitudinal direction of the driver IC in plan view. Theconnecting terminals 32, the connecting terminals 31, and the connectingterminals 32 are sequentially arranged in the X direction in plan view.The connecting terminals 32 are positioned closer to the fifth surface23 e or the sixth surface 23 f on a short side of the driver IC than theconnecting terminals 31 are positioned, in the X direction in plan view.

Similarly, the connecting terminals 35 and 34 are arranged to formcolumns as viewed in the X direction that is the longitudinal directionof the driver IC in plan view. The connecting terminals 35, theconnecting terminals 34, and the connecting terminals 35 aresequentially arranged in the X direction in plan view. The connectingterminals 35 are positioned closer to the fifth surface 23 e or thesixth surface 23 f on the short side of the driver IC than theconnecting terminals 34 are positioned, in the X direction in plan view.

The signal line drive circuit 23 of the first embodiment includes theinternal wires 39 that short-circuit the connecting terminals 32adjacent to each other inside the driver IC. The internal wires 39 maynot be provided depending on a driver IC, as described in a secondembodiment.

As illustrated in FIG. 7, a first bump 41, a second bump 48, a thirdbump 42, a fourth bump 45, a wire 44, inspection wires 43A, 43B, 43C,and 43D, an input/output bump 46, and inspection bumps 46A, 46B, 46C,and 46D are arranged on the pixel substrate 60, in addition to the wires200.

The first bumps 41 are electrically connected with the respective wires200. The input/output bump 46 is a connecting terminal that is joinedwith a connecting terminal of a flexible substrate (not illustrated).The wire 44 is a wire that connects the second bump 48 with theinput/output bump 46. The wires 44 are wires that extend toward aninside of the pixel substrate 60 from the respective input/output bumps46, and that transmit input/output signals between the driver IC and anexternal device. In this way, the second bumps 48 are electricallyconnected with the respective wires 44.

Typically, the number of the wires 200 is larger than the number of thewires 44. The first bumps 41 are arranged in a plurality of columns in astaggered manner, in the X direction in plan view. Therefore, the areaof the first bumps 41 is smaller than the area of the second bumps 48.

The third bumps 42 are dummy bumps not electrically connected with therespective wires 200. Similarly, the fourth bumps 45 are dummy bumps notelectrically connected with the respective wires 44.

The inspection bumps 46A, 46B, 46C, and 46D are connecting terminals forallowing electrical connection of inspection probes (not illustrated).

The inspection wires 43A and 43B are wires that electrically connect theinspection bumps 46A and 46B with the respective third bumps 42. In thefirst embodiment, the third bumps 42 are portions wider than theinspection wires 43A and 43B. However, parts of the inspection wires 43Aand 43B may serve as the third bumps 42 without wider portions.

The inspection wires 43C and 43D are wires that electrically connect theinspection bumps 46C and 46D with the respective fourth bumps 45. In thefirst embodiment, parts of the inspection wires 43C and 43D serve as thefourth bumps 45. However, portions wider than the inspection wires 43Cand 43D may be provided to serve as the fourth bumps 45.

The inspection wires 43A, 43B, 43C, and 43D are pulled out toward theoutside of the driver IC of the signal line drive circuit 23 in planview, as illustrated in FIG. 5. As illustrated in FIG. 7, one driver ICis connected with eight inspection wires 43A, 43A, 43B, 43B, 43C, 43C,43D, and 43D, and thus the eight inspection wires 43A, 43A, 43B, 43B,43C, 43C, 43D, and 43D are pulled out toward the outside of the onedriver IC.

As illustrated in FIG. 7, the connecting terminal 31 of the IC driveroverlaps the first bump 41 in plan view. The connecting terminal 34 ofthe IC driver overlaps the second bump 48 in plan view. The connectingterminal 32 of the IC driver does not overlap the first bump 41 or thesecond bump 48 in plan view. The connecting terminal 32 of the IC driveroverlaps the third bump 42 in plan view. The connecting terminal 35 ofthe IC driver does not overlap the first bump 41 or the second bump 48in plan view. The connecting terminal 35 of the IC driver overlaps thefourth bump 45 in plan view.

Connecting conductors 49 (see FIG. 9A) of the ACF on the substrate areprovided between the connecting terminals 31, 32, 34, and 35 of thedriver IC, and the first bump 41, the second bump 48, the third bump 42,and the fourth bump 45, which respectively overlap the connectingterminals 31, 32, 34, and 35 in plan view. The driver IC itself ispressed and crimped by a crimping head.

The ACF includes conductive particles, and an insulating adhesivecontaining the conductive particle. When the driver IC itself is pressedand crimped by the crimping head, the adhesive is cured in a state wherethe conductive particles are bonded together, between the connectingterminals 31, 34, 32, and 35 of the driver IC, and the first bump 41,the second bump 48, the third bump 42, and fourth bump 45, whichrespectively overlap the connecting terminals 31, 34, 32, and 35 in planview, thereby maintaining the electrical connection.

In the driver IC of the face-down method, it has been desired to confirmthat conductive particles are sufficiently pressurized and bondedtogether, and the electrical connection is established between theconnecting terminals 31 and 34 of the driver IC, and the first bump 41and the second bump 48, which respectively overlap the connectingterminals 31 and 34 in plan view. Therefore, in the first embodiment,respective electrical coupling states between parts of the connectingterminals 32 and 35, which are not used and are close to four corners ofthe driver IC of the face-down method, and the third bumps 42 and thefourth bumps 45 as dummy bumps, are detected.

As an inspection method of the first embodiment, firstly, the inspectionbumps 46A and 46B are electrically connected with respective inspectionprobes (not illustrated). A small current flows from the inspectionprobe to the inspection bump 46A. This small current is conductedthrough a path of the inspection wire 43A, the third bump 42, theconnecting conductor 49, the connecting terminal 32 of the driver IC,the internal wires 39, the connecting terminal 32 of the driver IC, theconnecting conductor 49, the third bump 42, and the inspection wire 43B.Then, the small current or the voltage thereof is detected by theinspection probe connected with the inspection bump 46B. A small currentmay flow from the inspection probe to the inspection bump 46B, and thesmall current that is conducted through a reverse path to theabove-described path or the voltage thereof may be detected by theinspection probe connected with the inspection bump 46A.

Similarly, the inspection bumps 46C and 46D are electrically connectedwith respective inspection probes (not illustrated). A small currentflows from the inspection probe to the inspection bump 46C. This smallcurrent is conducted through a path of the inspection wire 43C, thefourth bump 45, the connecting conductor 49, the connecting terminal 32of the driver IC, the internal wires 39, the connecting terminal 32 ofthe driver IC, the connecting conductor 49, the fourth bump 45, and theinspection wire 43D. Then, the small current or the voltage thereof isdetected by the inspection probe connected with the inspection bump 46D.The small current may flow from the inspection probe to the inspectionbump 46D, and the small current that is conducted through a reverse pathto the above-described path or the voltage thereof may be detected bythe inspection probe connected with the inspection bump 46C.

According to the above-described inspection, the respective electricalcoupling states between the connecting terminals 32 and 35, which arenot used and are close to the four corners of the driver IC of theface-down method, and the third bumps 42 and the fourth bumps 45 asdummy bumps, can be detected. As a result, the pressure contact state ofthe four corners of the driver IC can be grasped, and thus, even if adriver IC having a different shape is used, the pressure contact statecan be grasped. As a result, the number of the signal lines 25 handledby one driver IC can be increased. Therefore, increase in the number ofthe driver ICs can be prevented even if the resolution of the displayregion 21 is increased.

In the above description, the electrical connection between the driverIC of the signal line drive circuit 23 and the pixel substrate 60 hasbeen described. The above-described connecting configuration can beemployed for the electrical connection between the driver IC of thescanning line drive circuit 22, and the pixel substrate 60. The driverIC of the signal line drive circuit 23, and the driver IC of thescanning line drive circuit 22 have a similar configuration regardingthe electrical connection between the driver IC and the pixel substrate60. The electrical coupling state between the driver IC and thesubstrate can be detected before and after a reliability test, and thusthis connecting configuration can contribute to quality improvement.Even if the scanning line drive circuit 22 and the signal line drivecircuit 23 are configured as a single driver IC, the above-describedconnecting configuration can be employed regarding the electricalconnection between the driver IC and the pixel substrate 60.

As illustrated in FIG. 7, the first bumps 41 and the third bumps 42 arearranged to form a plurality of columns in the X direction in plan view.The third bumps 42, the first bumps 41, and the third bumps 42 aresequentially arranged in the X direction in plan view.

Similarly, the second bumps 48 and the fourth bumps 45 are arranged toform columns in the X direction in plan view. The fourth bumps 45, thesecond bumps 48, and the fourth bumps 45 are sequentially arranged inthe X direction in plan view.

By the way, as illustrated in FIG. 6, positions in the Y direction ofthe connecting terminals 31, 32, 34, and 35 of the first surface 23 aare close to either the third surface 23 c or the fourth surface 23 d. Acurve may appear such that a central portion in the Y direction of thefirst surface 23 a is recessed, as illustrated in FIG. 9B, due to aninfluence of coarse-dense distribution of the connecting terminals 31,32, 34, and 35. Therefore, as illustrated in FIG. 9B, when a comparisonis made among a position P1 of a first bump column (a column of thefirst bump 41 and the third bump 42), a position P2 of a second bumpcolumn (a column of the first bump 41 and the third bump 42), and aposition P3 of a third bump column (a column of the second bump 48 andthe fourth bump 45), from the third surface 23 c to the fourth surface23 d in the Y direction, a gap between the third bump 42 and theconnecting terminal 32 tends to be wider at the position P2.

The inspection wires 43A and 43B are connected with the respective thirdbumps 42 at the position P2 of the second bump column (the column of thefirst bump 41 and the third bump 42) that are provided inside, as viewedin the Y direction. That is, the connecting terminals 32 that overlapthe inspection wires 43A and 43B in plan view are arranged at theposition P2 of the second bump column that are provided inside in ashort direction of the driver IC. If the conductive particles aresufficiently pressurized and bonded together and the electricalconnection is established between the third bumps 42 and the connectingterminals 32 at the position P2, it can be assumed that the conductiveparticles are sufficiently pressurized and bonded together and theelectrical coupling is established between the first bump 41 and theconnecting terminal 31 at the position P2.

Second Embodiment

FIG. 10 is an enlarged schematic view illustrating connecting electrodesand wires of a substrate on which terminals of a driver IC according toa second embodiment are mounted. FIG. 11 is a schematic viewillustrating a cross section taken along line XI-XI in FIG. 10. The sameconfiguration elements as those described in the first embodiment aredenoted with the same reference signs, and overlapping description isomitted.

The arrangement illustrated in FIG. 10 can be mirror-inverted withrespect to a Y direction, like FIG. 7, and thus only the left side isdescribed. Therefore, two connecting terminals 32, a plurality ofconnecting terminals 31, and two connecting terminals 32 aresequentially arranged in an X direction in plan view.

A driver IC of the second embodiment does not include internal wires 39,which are provided inside the driver IC of the signal line drive circuit23 illustrated in FIG. 6. Therefore, even if two inspection wires 43Aand 43B overlap respective connecting terminals 32 adjacent to eachother in plan view, the two inspection wires 43A and 43B cannot conducteach other, like the first embodiment. Therefore, it is necessary todevise a method of routing the inspection wires 43A and 43B.

As illustrated in FIG. 10, end portions of the inspection wires 43A and43B are third bumps 43 a and 43 b, respectively. Then, both the thirdbumps 43 a and 43 b overlap the connecting terminals 32 and 32 adjacentto each other in plan view. As a result, the third bump 43 a and thethird bump 43 b are short-circuited through the connecting terminals 32if the electrical connection between the third bumps 43 a and 43 b, andthe connecting terminals 32 is established through connecting conductors49, as illustrated in FIG. 11.

As an inspection method of the second embodiment, firstly, inspectionbumps 46A and 46B are electrically connected with respective inspectionprobes (not illustrated). A small current flows from the inspectionprobe to the inspection bump 46A. This small current is conductedthrough a path of an inspection wire 43A, the third bump 43 a, theconnecting conductor 49, the connecting terminal 32 of the driver IC,the connecting conductor 49, the third bump 43 b, and an inspection wire43B. Then, the small current or the voltage of the small current isdetected by the inspection probe connected with the inspection bump 46B.A small current may flow from the inspection probe to the inspectionbump 46B, and the small current that is conducted through a reverse pathto the above-described path or the voltage thereof may be detected bythe inspection probe connected with the inspection bump 46A.

First Modification of Second Embodiment

FIG. 12 is an enlarged schematic view illustrating connecting electrodesand wires of a substrate on which terminals of a driver IC according toa first modification of the second embodiment are mounted. The sameconfiguration elements as those described in the first embodiment andthe second embodiment are denoted with the same reference signs, andoverlapping description is omitted.

The arrangement illustrated in FIG. 12 can be mirror-inverted withrespect to a Y direction, like FIG. 7, and thus only the left side isdescribed. Therefore, one connecting terminal 32, a plurality ofconnecting terminals 31, and one connecting terminal 32 are sequentiallyarranged in an X direction in plan view.

As illustrated in FIG. 12, end portions of inspection wires 43A and 43Bare third bumps 43 a and 43 b. Then, both the third bumps 43 a and 43 boverlap one connecting terminal 32 in plan view. As a result, the thirdbumps 43 a and 43 b are short-circuited through the connecting terminal32 if the electrical connection between the third bumps 43 a and 43 b,and the connecting terminal 32 is established through a connectingconductor 49, as illustrated in FIG. 11.

A display device of the first modification of the second embodiment candetect the respective electrical coupling states between connectingterminals 32 and 35, which are not used and are close to four corners ofthe driver IC of the face-down method, and third bumps 42 and fourthbumps 45 as dummy bumps, even if only one connecting terminal 32 isprovided on one side. Accordingly, similar functions and effects tothose of the first and second embodiments can be obtained.

Second Modification of Second Embodiment

FIG. 13 is an enlarged schematic view illustrating connecting electrodesand wires of a substrate on which terminals of a driver IC according toa second modification of the second embodiment are mounted. The sameconfiguration elements as those described in any of the firstembodiment, the second embodiment, and the first modification of thesecond embodiment are denoted with the same reference signs, andoverlapping description is omitted.

The arrangement illustrated in FIG. 13 can be mirror-inverted withrespect to a Y direction, like FIG. 7, and thus only the left side isdescribed. Therefore, two connecting terminals 32, a plurality ofconnecting terminals 31, and two connecting terminals 32 aresequentially arranged in an X direction in plan view.

As illustrated in FIG. 13, end portions of inspection wires 43A and 43Bare third bumps 43 a and 43 b. Then, both the third bumps 43 a and 43 boverlap one connecting terminal 32 in plan view. That is, in the secondmodification of the second embodiment, the third bumps 43 a and 43 boverlap only outer one of two connecting terminals 32 provided in thesame column in plan view. As a result, the third bumps 43 a and 43 b areshort-circuited through the connecting terminal 32 if the electricalconnecting between the third bumps 43 a and 43 b, and the connectingterminal 32 is established through a connecting conductor 49, asillustrated in FIG. 11.

A display device of the second modification of the second embodiment candetect the respective electrical coupling states between connectingterminals 32 and 35, which are not used and are close to four corners ofthe driver IC of the face-down method, and third bumps 42 and fourthbumps 45 as dummy bumps, as long as one connecting terminal 32 can beused even if the plurality of connecting terminals 32 are provided onone side. Accordingly, similar functions and effects to those of thefirst and second embodiments and the first modification of the secondembodiment can be obtained.

Third Embodiment

FIG. 14 is an enlarged schematic view illustrating connecting electrodesand wires of a substrate on which terminals of a driver IC according toa third embodiment are mounted. The same configuration elements as thosedescribed in any of the first embodiment, the second embodiment, and themodifications of the second embodiment described above are denoted withthe same reference signs, and overlapping description is omitted.

Similarly to the first embodiment, the driver IC in the third embodimentincludes internal wires 39 that short-circuit connecting terminals 32adjacent to each other inside the driver IC of a signal line drivecircuit 23 illustrated in FIG. 6. As illustrated in FIG. 6, theconnecting terminals 32 are positioned closer to a fifth surface 23 e ora sixth surface 23 f on a short side of the driver IC than connectingterminals 31 are positioned, in an X direction in plan view. Similarlyto the first embodiment, a plurality of first bumps 41 and a pluralityof third bumps 42 are arranged to form a plurality of columns, in the Xdirection in plan view. The third bumps 42, the first bumps 41, and thethird bumps 42 are sequentially arranged, in the X direction in planview. The connecting terminals 32 overlapping inspection wires 43A and43B in plan view are provided inside in a short direction (Y direction)of the driver IC. The third embodiment includes the inspection wires43A, 43B, 43C, and 43D, thereby detecting the respective electricalcoupling states between connecting terminals 32 and 35, which are notused and are close to four corners of the driver IC of the face-downmethod, and third bumps 42 and fourth bumps 45 as dummy bumps.

By the way, the inspection wires 43A, 43B, 43C, and 43D may beelectrically charged depending on an environment where the displaydevice 1 is placed.

When the inspection wires 43C and 43D are electrically charged, even ifthe charge is transferred to the fourth bumps 45 so that staticelectricity is transferred to the second bumps 48, it is possible toprevent its influence on the display region 21, because there is anenough distance between the first bump 41 and the fourth bump 45.However, the distance between the first bump 41 and the third bump 42 issmaller than the distance between the first bump 41 and the fourth bump45. Therefore, when the inspection wires 43A and 43B are electricallycharged, the charge is transferred to the third bumps 42 so that staticelectricity may be transferred to the first bumps 41. When the staticelectricity is transferred to the first bumps 41, the static electricitymay be transferred to the wires 200, which may destroy the thin filmtransistors Tr illustrated in FIG. 4.

Therefore, the inspection wires 43A and 43B of the third embodimentincludes at least one fuse portion 47. To be specific, as illustrated inFIG. 14, the inspection wires 43A and 43B each have three fuse portions47. The inspection wires 43A and 43B may each include five or ten fuseportions 47.

The fuse portion 47 corresponds to a part of each of the wires 43A and43B that is narrower in width than a basic width W0 of the inspectionwires 43A and 43B. A first narrow width portion has a length L1 and awidth W1, a second narrow width portion has a length L2 and a width W2,and a third narrow width portion has a length L3 and a width W3. Theratio of the width to the length of the narrow width portion (W1/L1,W2/L2, or W3/L3) can be appropriately set. However, if the ratio is fromabout 1.5/100 to 20/100, there is a higher possibility that the fuseportion 47 sparks and breaks down in the range of a withstand voltagethat occurs in the manufacturing process of the display device. Thewidth W1, W2, or W3 is favorably 1.5 μm or more so that a conductor canbe stably formed in an exposure device. The influence caused by thelength L1, L2, or L3 on the withstand voltage of the fuse portion 47 issmaller than that is caused by the width W1, W2, or W3. However, thewithstand voltage can be adjusted by making the lengths L1, L2, and L3different from one another.

The inspection wires 43A and 43B are routed at the fixed basic width W0without being made thick on the inspection bumps 46A and 46B sides,respectively, and the wiring area is made small, whereby the charge onthe inspection wires 43A and 43B can be reduced.

The inspection wires 43A and 43B each including the fuse portions 47extend near the first bumps 41. However, even if the inspection wires43A and 43B are electrically charged, the fuse portions 47 sparks due tothe charge before the charge is transferred to the third bumps 42. As aresult, there is a lower possibility that static electricity istransferred to the first bumps 41, and there is a lower possibility thatthe static electricity is transferred to the wires 200, therebydestroying the thin film transistors Tr illustrated in FIG. 2.

First Modification of Third Embodiment

FIG. 15 is an enlarged schematic view illustrating connecting electrodesand wires of a substrate on which terminals of a driver IC according toa first modification of the third embodiment are mounted. The sameconfiguration elements as those described in any of the firstembodiment, the second embodiment, and the modifications of the secondembodiment are denoted with the same reference signs, and overlappingdescription is omitted.

Similarly to the second modification of the second embodiment, thedriver IC according to the first modification of the third embodimentdoes not include internal wires 39 that shorts-circuit connectingterminals 32 adjacent to each other inside a driver IC of a signal linedrive circuit 23 illustrated in FIG. 6. Similarly to the secondmodification of the second embodiment, in the first modification of thethird embodiment, both the third bumps 43 a and 43 b overlap only outerone of two connecting terminals 32 in the same column in plan view.Similarly to the second modification of the second embodiment, the thirdembodiment includes the inspection wires 43A, 43B, 43C, and 43D, therebydetecting the respective electrical coupling states between connectingterminals 32 and 35, which are not used and are close to four corners ofthe driver IC of the face-down method, and third bumps 42 and fourthbumps 45 as dummy bumps, as long as one connecting terminal 32 can beused even if the plurality of connecting terminals 32 are provided onone side. Accordingly, similar functions and effects to those of thefirst and second embodiments and the first modification of the secondembodiment can be obtained.

The inspection wires 43A and 43B of the first modification of the thirdembodiment include at least one fuse portion 47. To be specific, asillustrated in FIG. 15, the inspection wires 43A and 43B each have threefuse portions 47.

The fuse portions 47 spark due to a charge before the charge istransferred to the third bumps 42. As a result, there is a lowerpossibility that static electricity is transferred to first bumps 41,and there is a lower possibility that the static electricity istransferred to wires 200, thereby destroying thin film transistors Trillustrated in FIG. 2.

Evaluation of Third Embodiment

FIGS. 16A to 16C are explanatory diagrams for describing evaluationexamples of the third embodiment. The same configuration elements asthose described in the third embodiment are denoted with the samereference signs, and overlapping description is omitted.

FIG. 16A illustrates, as a first evaluation example, a schematic diagramwhere the inspection wire 43A is made straight. The three fuse portions47 of the first evaluation example are arranged at uniform intervals ina length direction. W0 is 40 μm. The relation W1=W2=W3=10 μm holds, andthe relation L1=L2=L3=100 μm holds.

FIG. 16B illustrates, as a second evaluation example, a schematicdiagram where the inspection wire 43A is made straight. The fuseportions 47 of the second evaluation example are arranged such that therespective lengths are made different. W0 is 40 μm. The relationW1=W2=W3=10 μm holds. L1 is 200 μm, L2 is 100 μm, and L3 is 20 μm.

FIG. 16C illustrates, as a third evaluation example, a schematic diagramwhere the inspection wire 43A is made straight. The fuse portions 47 ofthe third evaluation example are arranged such that the width of thefuse portion 47 of the third evaluation example is made narrower thanthat of the fuse portion 47 of the second evaluation example. W0 is 40μm. The relation W1=W2=W3=5 μm holds. L1 is 200 μm, L2 is 100 μm, and L3is 20 μm.

A voltage of 1.0 kV or higher was applied between one end and the otherend in the first to third evaluation examples, and the state of the fuseportions 47 after the application was observed with a microscope.

In the first evaluation example, no breakdown of the fuse portions 47occurred even if 5.0 kV was applied between the one end and the otherend. In the first evaluation example, breakdown of the fuse portions 47was caused when 6.0 kV was applied between the one end and the otherend.

In the second evaluation example, no breakdown of the fuse portions 47occurred even if 2.5 kV was applied between the one end and the otherend. In the second evaluation example, breakdown of the fuse portions 47was caused when 3.0 kV was applied between the one end and the otherend.

In the third evaluation example, no breakdown of the fuse portions 47occurred even if 1.2 kV was applied between the one end and the otherend. In the third evaluation example, breakdown of the fuse portions 47was caused when 1.4 kV was applied between the one end and the otherend.

As described above, a breakdown voltage can be defined by making thethickness of a part of the fuse portions 47 of the inspection wirethinner than the thickness of the other fuse portions.

Preferred embodiments of the present invention have been described.However, the present invention is not limited by these embodiments. Thecontent disclosed in the embodiments is merely an example, and variousmodifications can be made without departing from the gist of the presentinvention. The appropriate modifications made without departing from thegist of the present invention obviously belong to the technical scope ofthe present invention.

For example, a liquid crystal display device has been described as thedisplay device 1 of the embodiments. However, the display device 1 canbe applied to a display device that lights a self-luminous body such asan organic light emitting diode (OLED). A plurality of driver ICs as thescanning line drive circuit 22 illustrated in FIG. 5 may be provided.The wires 100 illustrated in FIG. 5 may be arranged outside the fourthside 21 d of the display region 21, instead of outside the second side21 b of the display region 21. The wires 100 illustrated in FIG. 5 maybe arranged outside the fourth side 21 d of the display region 21, inaddition to outside the second side 21 b of the display region 21.Further, the configuration elements of the above-described embodimentscan be appropriately combined.

The present invention can naturally provide other advantageous effectsthat are provided by the aspects described in the embodiments above andare clearly defined by the description in the present specification orappropriately conceivable by those skilled in the art.

What is claimed is:
 1. A display device comprising: a substrateincluding a display region and a non-display region that is disposed ona periphery of the display region; at least one driver IC including aplurality of connecting terminals, and having a first surface that isfixed to face the non-display region; a plurality of first wires thatsupply a signal to the display region; a plurality of first bumpselectrically connected with the respective first wires; a plurality ofsecond wires that input and output a signal from and to an outside; aplurality of second bumps electrically connected with the respectivesecond wires; a plurality of inspection wires; and a plurality ofinspection bumps electrically connected with the respective inspectionwires, wherein the connecting terminals of the at least one driver ICcomprise a plurality of first connecting terminals overlapping therespective first bumps or the respective second bumps in plan view, anda plurality of second connecting terminals not overlapping the firstbumps or the second bumps in plan view, the inspection wires include aconnecting conductor between themselves and at least one of the secondconnecting terminals, and are pulled out to an outside of the at leastone driver IC in plan view, and a first end of each of the inspectionwires is electrically connected with one of the inspection bumps, and aset of second ends of two of the inspection wires overlaps with at leastone of the second connecting terminals in plan view.
 2. The displaydevice according to claim 1, wherein the connecting terminals arearranged to form a plurality of columns in a longitudinal direction ofthe at least one driver IC in plan view, and the second connectingterminals overlapping the inspection wires in plan view are arranged ininside columns among the columns in a short direction of the driver IC.3. The display device according to claim 1, wherein one of the secondconnecting terminals, the first connecting terminals, and one of thesecond connecting terminals are sequentially arranged in a longitudinaldirection of the at least one driver IC in plan view.
 4. The displaydevice according to claim 1, wherein the second connecting terminals,the first connecting terminals, and the second connecting terminals aresequentially arranged in a longitudinal direction of the at least onedriver IC in plan view.
 5. The display device according to claim 1,wherein the second connecting terminals are closer to a short side ofthe at least one driver IC than the first connecting terminals are, in alongitudinal direction of the at least one driver IC in plan view. 6.The display device according to claim 1, wherein eight of the inspectionwires are pulled out to an outside of the at least one driver IC in planview.
 7. The display device according to claim 1, wherein the set of thesecond ends of two of the inspection wires overlaps two or more of thesecond connecting terminals in plan view.